Battery powered clocks

[oilyriser]

I figured those plug in clocks cost more to operate than battery powered ones, and I wouldn't have to worry about power failures with the battery ones, so I unplugged the wall plug ones, and replaced them with battery powered ones. Then my scientific mind started noticing that some of the clocks would wear down their batteries faster than others. So today I got out my meter, and measured things.

I found the clocks stamped Made in USA, and one Made in Thailand all used 115 microamps or less, which means about 2 years of life out of one AA cell. The other clocks which ate batteries faster, measured 150 microamps and about 140. Those ones were stamped......


take a guess.

 

[Steve S]

Not much good comes from there.

 

[oilyriser]

the same country also sells batteries

 

[JHZR2]

so how much power does a plug-in unit use???

What are the costs for batteries? are you sure battery-powered units really cheaper over the lifecycle?

JMH

 

[oilyriser]

Plug in clocks use two or three watts, and three watts for a year is 26 kW-hrs, which would cost about four dollars if you pay 15 cents a kw-hr. One good AA cell costs about 50 cents, and will run a good clock for 2 years, so that's 25 cents a year. And they're cordless. The drawback is the battery clocks aren't lit up.

 

[Papa Bear]

Made in Canada ??

 

[MolaKule]

The newer generation CMOS integrated circuits use less current all the time. We design them and the Japaneese, Koreans, and Chinese build them.

 

[oilyriser]

I think it mostly depends on the design of the coil driver circuit. If you shape the pulse just right, all the energy is converted into a magnetic field, which moves the clock, rather than heating up the coil. LCD clocks take maybe 2 microamps, so the clock circuit is a very small part of the power use.

Maybe I should switch to powdered laundry detergent to save the same amount of money.

 

[Shannow]

Originally Posted By: oilyriser
The other clocks which ate batteries faster, measured 150 microamps and about 140. Those ones were stamped......


take a guess.


I think it's the same region that is selling split air conditioning systems for $400 in Bunnings.

The initial surge is massive, and their running draw is ridiculous.

If legislations was passed that didn't give people the option of buying a cheap air con (con being the operative word), we wouldn't need a new power station in the next 5 years.

 

[Al]

Originally Posted By: oilyriser
the same country also sells batteries

If batteries have lead in them..yea..they sell them.

 

[Shannow]

LOL

 

[Al]

What time is it where you are Shannow?

 

[eljefino]

One benefit to plug-in types is if you trust you're getting 60 Hz, you'll have an accurate clock.

 

[oilyriser]

solar powered

 

[Shannow]

Originally Posted By: Al
What time is it where you are Shannow?

9:28 PM at last post.

7:36 AM now and I'm munching toast and sipping tea

 

[moribundman]

I know the topic says "battery-powered clocks," but not one person here has so far mentioned a mechanical clock. Especially a regulator will keep time very well. A weight-driven pendulum clock can achieve an accuracy of +/- 1 second per month with very high consistency for decades. As for alarm clock, only one of those mechanical wind-up alarm clocks will possibly wake me.

 

[oilyriser]

There's at least one manufacturer that makes a wind-up electronic clock. It has a tiny electric generator powered by the spring.

 

[andyd]

I use worn out flash light batterys to run the pair I have. They will often last a yr or more

 

[moribundman]

Originally Posted By: oilyriser
There's at least one manufacturer that makes a wind-up electronic clock. It has a tiny electric generator powered by the spring.


Google "Seiko Spring Drive," if you care about this sort of thing in a watch.